Korean portable audio giant Astell & Kern has just released two new instruments: the new flagship AK380 and the entry-level AK Jr, which we’re launching today. AK Jr emphasizes lightness, thinness, and affordability. “Jr” is short for “junior,” and its HiFiReport says “Don’t look down on me because I’m junior. I’m Astell & Kern!” Let’s take a closer look at the actual device.
This time, we have Nobita Nobi as our model. The Jr comes in a black paper box with a large logo on the front.
Like previous AK products, the packaging is simple and clear, matching current smartphone packaging styles.
The details on the back of the box show 64GB of built-in storage, which is very generous.
A Micro-B USB cable is included for charging and data transfer.
A simple quick start guide is provided, and the full manual can be downloaded from the official website.
Screen and back protectors are included in the manual. Remember to use them. Protective films are included out of the box for the AK240, which appears to be standard AK equipment.
Wait, why are there two devices? Basically, one is the official retail version, and the other is a media test unit (with pre-print). The test unit comes in a white box. In this unboxing, the distributor has exclusively offered a new retail unit. During testing, of course, we used a media test unit. They are identical, except the test unit has 16GB of built-in memory.
The main selling point of the Jr is its small and simple design. This is the official image comparing it to other products in its range, which clearly shows a significant reduction in thickness, at only 8.9mm.
For a personal comparison, I put it next to my SONY Z2 smartphone. The AK Jr is definitely very light and thin. Yes, the screen sizes are different, but the Jr’s 3.1″ screen is enough to view album art and track information, without the need to browse the web.
SONY Z2: Dimensions 146.8 x 73.3 x 8.2 mm, Weight 158g, 5.2″ Screen
AK Jr: Dimensions 117.0 x 52.9 x 8.9 mm, Weight 93g, Screen 3.1″
This side view image highlights the difference in thickness. The Jr has a Micro SD card slot on the right side, which supports up to 64GB. Combined with the built-in 64GB, the total capacity can reach 128GB. You can also fit multiple Micro SD cards if you have a very extensive music library! Personally, I usually find the built-in storage to be sufficient. I only upload the music I intend to listen to, rather than filling it with everything. There is also a circular volume control dial.
The rear of the Jr is made of aluminum, with a texture similar to carbon fiber.
The Micro-B USB port is located at the bottom.
On the left side are three basic buttons for controlling playback.
The power button and 3.5mm headphone output jack are located on the top.
The operation is very simple and easy to get started with. You probably won’t even need to read the manual. Just long press the power button to turn it on or off. After booting, you can go to settings and set the interface language to English. Some settings are similar to smartphones, and you can customize them according to your preferences.
The device comes preloaded with several songs, so you can plug in your headphones and start listening right away. I started by connecting my UE 10 in-ear monitors. My first impression of the sound is a large soundstage, balanced frequency response, and ample power. The first two features were particularly surprising and different from my previous impressions of AK players. Previously, AK players did not have such a large soundstage, focusing more on precise instrument placement.
The frequency response of the Jr is very balanced, without any kind of missing or excessive sound range.
This is the volume control screen. It can be adjusted using the dial on the right or directly via the touch screen. The maximum volume level is 75.
Equalizer (EQ) is included to customize the sound.
You can also view detailed track information.
When a Micro SD card is inserted, the Jr automatically scans it and integrates it into the music library.
Next, I tried listening with HiFiMAN 400i headphones. The Jr drives them without problems and maintains a balanced frequency response, which I really appreciate. One of the reasons I’ve always disliked headphone systems so much is that their frequency response often lacks the fullness and balance of two-channel speaker systems.
The Jr’s output is 14% higher than the AK100’s 1.5 VRMS, at 1.95 VRMS, and its impedance is reduced to 2 Ohms (compared to the AK100’s 22 Ohms). This results in more drive power, which explains why it drives the 400i headphones so well!
The Jr can record DSD 2.8MHz files, although it converts them to PCM first before recording them. Additionally, the Jr can be used as a USB DAC.
Details of AK Jr
* **Body Color**: Mixed Silver
* **Body Material**: Aluminum
* **Display**: 3.1-inch WQVGA (200×400) Touch Screen
* **Supported Audio Formats**: WAV, FLAC, WMA, MP3, OGG, APE (Standard, Advanced, Fast), AAC, ALAC, AIFF, DFF, DSF
* **Sample Rate**:
* FLAC, WAV, ALAC, AIFF : 8kHz ~ 192kHz (8/16/24bits per sample)
* DSD : DSD64 (1bit 2.8MHz), Stereo (DSD to PCM)
* **Output Level**: 1.95Vrms
* **DAC**: Wolfson WM8740 x1 (Single DAC)
* **Recording**: Up to 24bit/192kHz
* **Input**: USB Micro-B port (for charging and data transfer)
* **Output**: 3.5mm TRS
* **Bluetooth**: V4.0
* **Dimensions**: 2.08” (52.9 mm) [W] x 4.60″ (117 mm) [H] x 0.35″ (8.9 mm) [D]
* **Weight**: 3.28 oz (93g)